SHANGHAI/BERLIN (Reuters) - Chinese Premier Li Keqiang has called for China and Germany to play a leading role to ensure the stability of international markets amid an uncertain climate, the official Xinhua news agency said late on Wednesday.

During a call with German Chancellor Angela Merkel, Li said "international political and economic scenes are facing several uncertain factors," Xinhua reported.

"China and Germany should send stable signals to the global markets and jointly safeguard the existing international system through trade and investment liberalization," Xinhua said, citing Li.

A German government spokesman said Merkel and Li vowed to support free trade and a stable environment to foster international business relations.

"The negotiations about a European-Chinese investment agreement should therefore be concluded quickly," the spokesman said.

He added that Li accepted Merkel's invitation to visit Germany soon. "During this visit, economic and trade-related issues should be discussed more deeply," the spokesman said.

Amid a turbulent start by new U.S. President Donald Trump, whose first days have been marked by media feuds and protests, China has been playing up its role as a steadying force from global trade to climate change.

Chinese President Xi Jinping, as a keynote speaker at the World Economic Forum in Davos, Switzerland, also offered a vigorous defense of globalization and signaled Beijing's desire to play a bigger role on the world stage.

Meanwhile, Trump, who took office last Friday, has already signed an order withdrawing the United States from the Trans-Pacific Partnership trade pact and threatened trade curbs, including a border tax on cars that Germany's BMW <BMWG.DE> plans to build at a new factory in Mexico.

Li also said China would continue as a "staunch supporter" of European integration, amid growing pressure on the bloc following a vote in Britain last year to leave the European Union. Trump has said Brexit could be a "great thing".

(Reporting by Adam Jourdan in Shanghai and Michael Nienaber in Berlin; Editing by Michael Perry and Robin Pomeroy)